Some modern laptops have both USB 2.0 and 3.0 controllers. In this case single USB 3.0 controller can handle with four PS Eye cameras at 640x480 at 60 FPS.

Some modern laptops have both USB 2.0 and 3.0 controllers. In this case single USB 3.0 controller can handle with four PS Eye cameras at 640x480 at 60 FPS.

−

{{Important|Kinect 2 for Windows, Kinect for Xbox One requires USB 3.0 controller. Kinect SDK 2.0 currently supports only single sensor on one PC.}}

+

{{Important|Kinect 2 for Windows, Kinect for Xbox One requires USB 3.0 controller. Kinect SDK 2.0 supports only single sensor on one PC. [[Multiple_Kinects_v2_on_a_Single_PC|Libfreenect2]] supports multiple sensors on one PC.}}

You can check how many USB 2.0 / 3.0 controllers you have in the “Universal Serial Bus controllers” section in Device Manager. Operating system will display USB 2.0 controllers as ''USB Enhanced Host Controller'' (not to be mistaken with USB 1.0 ''USB Universal Host controller''). USB 3.0 controller usually works in USB 2.0 mode, so it will be represented by 2 items - ''USB 3.0 Host Controller'' and ''USB Enhanced Host Controller''

You can check how many USB 2.0 / 3.0 controllers you have in the “Universal Serial Bus controllers” section in Device Manager. Operating system will display USB 2.0 controllers as ''USB Enhanced Host Controller'' (not to be mistaken with USB 1.0 ''USB Universal Host controller''). USB 3.0 controller usually works in USB 2.0 mode, so it will be represented by 2 items - ''USB 3.0 Host Controller'' and ''USB Enhanced Host Controller''

Line 300:

Line 300:

|Microsoft Kinect v2

|Microsoft Kinect v2

|Etron EJ168

|Etron EJ168

−

|Does not work.

+

|No data coming from device.

|

|

|-

|-

|Microsoft Kinect v2

|Microsoft Kinect v2

|VIA VL800

|VIA VL800

−

|Does not work.

+

|No data coming from device.

|

|

|-

|-

Latest revision as of 10:31, 5 February 2019

You can order software and hardware as one package from CamVFX, our official US Reseller.

Cameras Comparison

Which camera to choose?

Specification

Sony PS Eye

Logitech C922

Winner

Comments

practical frame rate(s)

50 FPS, 60 FPS

60 FPS

PS Eye

In some cases it is more practical to record at 50 FPS instead of 60 FPS, but C922 doesn't support 50 FPS. Also, PlayStation Eye has more stable frame rate: exactly 60 frames per second, while C922 could drop separate frames time after time and a result actual FPS is slightly smaller than 60.

practical resolution(s)

640x480

1280x720

it depends

For iPi Motion Capture it is not so important to have high resolution. Higher resolution just allows to stand farther from camera, which potentially increases maximum capture area. But from the other side, higher resolution means slower processing in iPi Mocap Studio. Thus if your top priority is the biggest capture area, then Logitech C922 wins. In other case - PS Eye wins.

field of view

diagonal: 75°horizontal: 63°vertical: 49.5°

diagonal: 78°horizontal: 70°vertical: 43°

PS Eye

PS Eye has slightly bigger vertical field of view. Therefore an actor can stand closer to camera and still be visible in full length.

optic distorsion

low

low

draw

Both cameras have good-enough optics for iPi Motion Capture needs.

image quality

good-enough(but poor in low light conditions)

good(good-enough in low light conditions)

C922

But image quality is not so critical for iPi Motion Capture.

connection

USB 2.0(up to 2-4 cameras per USB-controller)

USB 2.0(up to 2-4 cameras per USB-controller)

draw

Not more than two cameras should be connected to each USB controller to capture at 50 or 60 FPS. But some USB 3.0 controllers can handle up to four cameras at 50 and 60 FPS. This is true for both camera models.

disk usage(for six cameras)

25 MB/sec640x480@60(background subtraction)

35 MB/sec1280x720@60(raw JPEG frames obtained from cameras)

PS Eye

CPU load is higher as well when recording with Logitech C922.

tripod mounting screw

no

yes

C922

price

under 10 USD

about 90 USD

PS Eye

Prices may differ for different regions. But in any case PS Eye is significantly cheaper.

Action Cameras

Stand-alone cameras that meet requirements below can be used instead of web cameras.

Note: Stand-alone cameras support in available starting from v4 of iPi Motion Capture.

Requirements for stand-alone cameras:

Fixed optics (if camera has auto-focus and zoom features, they must be turned off before recording)

High FPS (at least 60 FPS at 720p resolution)

Wide field-of-view (at least 90° in diagonal)

You can even mix cameras of different models. But all cameras must support one and the same pair of FPS and resolution.

Tip: The most practical resolution for full body motion capture is 720p that is 1280 x 720. Using higher resolutions adds technical complications but does not give substantial advantages.

Action cameras fully meet the requirements. The most popular models here are:

But you can use other (more affordable) models: [1]. Or even smartphones.

Note: If you select action cameras specially for iPi Motion Capture, you can use almost any cheap action camera model which supports 720p (1280 x 720) resolution at 60 or 90 FPS. At least, there is no need to choose cameras that support 4K video because such high resolution is not practical for iPi Motion Capture.

Cables

Note: In case of using of action cameras there is no need in these USB cables.

For distances over 3m, you should use active USB 2.0 extension cables (aka USB repeaters). You can daisy-chain multiple active USB 2.0 extension cables for distances longer than 10m.

When combining active and passive cables, make sure that connection order is correct (computer->active cable->passive cable->camera).

Tip: Microsoft Kinect v2 is an USB 3.0 device, thus it would require USB 3.0 extension cables. However, because each Kinect v2 requires a separate computer for operation, there is usually no need in extension cables, because computers can be placed appropriately.

Tripods

Inexpensive 40- or 50-inch tripods like
[2]
should be fine for use with iPi Desktop Motion Capture. It is recommended to place at least one of the cameras reasonably high (2 or 3 meters high) so you may need a high (72 inch or higher) tripod like [3] or some kind of ad hoc wall mounting solution.

Mini Maglite (or other flashlight) for calibration

You will need a small bright object for calibration. It is recommended to get Mini Maglite for that purpose:

If you cannot get a Mini Maglite, you can use some other similar flashlight:

Alternatively, you can use Sony Move motion controller with white light turned on.

Video Card

iPi Mocap Studio heavily relies on GPU for calculations. Therefore, it is recommended to use a fast GPU for processing recorded videos. The support for DirectX 11 is required (most of the video cards released since 2010 meet this requirement).

Please be aware that desktop GPUs are dramatically faster than laptop GPUs (due to apparent thermal constraints in laptop PCs). Laptops with Switchable Graphics should be configured to run iPi Mocap Studio on a discrete (high-performance) GPU.

Note: Professional GPUs like NVIDIA Quadro or AMD FirePro are not recommended due to high price and lack of performance advantage. You should understand that Quadro/FirePro video cards are designed for very specific professional OpenGL-based workloads. Their main advantage is high image quality in OpenGL rendering. iPi Motion Capture needs raw 32-bit floating point performance and does not benefit from image quality features of Quadro/FirePro video cards. For best performance, use top gaming-class video cards from NVIDIA GeForce GTX or AMD Radeon R9 series.

USB controllers

Note: In case of using of action cameras there is no special requirements for USB controllers.

All modern computers (e.g. dual-core and better) based on Intel, AMD and Nvidia chipsets have at least two USB 2.0 controllers on board. With two USB 2.0 controllers you've got enough bandwidth to record with:

2 depth sensors (first generation Microsoft Kinect)

or 4 cameras at 640x480 at 60 FPS

or 6 cameras at 640x480 at 40 FPS

Some modern laptops have both USB 2.0 and 3.0 controllers. In this case single USB 3.0 controller can handle with four PS Eye cameras at 640x480 at 60 FPS.

Important! Kinect 2 for Windows, Kinect for Xbox One requires USB 3.0 controller. Kinect SDK 2.0 supports only single sensor on one PC. Libfreenect2 supports multiple sensors on one PC.

You can check how many USB 2.0 / 3.0 controllers you have in the “Universal Serial Bus controllers” section in Device Manager. Operating system will display USB 2.0 controllers as USB Enhanced Host Controller (not to be mistaken with USB 1.0 USB Universal Host controller). USB 3.0 controller usually works in USB 2.0 mode, so it will be represented by 2 items - USB 3.0 Host Controller and USB Enhanced Host Controller

Alternatively, you can use USBView utility from Microsoft which allows to view all USB controllers and devices in a more convenient way: Download USBView

You should make sure that you have depth sensors or cameras evenly distributed between available USB 2.0 (or 3.0) controllers. For example, if you have four PS Eye cameras, you should connect two cameras to first controller and two cameras to second controller. (But some USB 3.0 controllers can work with four cameras.) Device Manager usually shows USB cameras as “USB Composite Device” at the “Advanced” tab of USB controller properties. If you have too many cameras connected to single USB 2.0 / 3.0 controller, you should re-plug them to different USB ports.

USB hubs

Note: In case of using of action cameras there is no need in these USB hubs.

If several devices are connected on the USB hub and working in parallel, then the USB bandwidth is shared among the devices. Connecting all cameras via single USB 2.0 hub is OK only for low resolution video recording (320x240). To be able to record video at 640x480 and 60 frames per second, you should avoid connecting more than 2 cameras via single USB 2.0 controller and more than 4 cameras via some models of USB 3.0 controllers.

Solution if your PC lack USB controllers

If you do not have enough USB controllers, you can either add USB controller to your PC, or use several PCs and Distributed Recording feature.

For desktops you can use PCI USB controllers.

For laptops there are USB controllers for ExpressCard and eSATA slots.

Potential issues with USB controllers

Some USB chips have compatibility issues with specific cameras which may result in not detecting cameras, low frame rate, etc. See the next section on known issues.

Many modern laptops have one of the integrated USB 2.0 controllers reserved for docking station. That may effectively halve your USB bandwidth. So laptops with a large number of USB ports (4 or more) are preferrable. Desktop PCs should not have such problem.

Important! Before buying a specific laptop model it is strongly recommended to ensure it has the sufficient number of available built-in USB controllers and they are compatibile with cameras you intend to use. Find it at your local retailer, and bring cameras with you to test. Though it may be easier if your friend/neighbour has such a laptop. Or ask at our forum, maybe someone already used this model with our software or can recommend specific model for your camera configuration.

If you plan getting an additional USB controller, please be aware of potential problems with USB 2.0 controllers available on the market. Many USB 2.0 controllers are based on defective NEC USB 2.0 chip, not capable of standard USB 2.0 speeds. That's a well-known bug specific only to NEC USB 2.0 chip. By contrast, all NEC USB 3.0 chips are good and do not have this problem.

Some manufacturers sell what they call a "USB 2.0 ExpressCard" controller for laptops. Many of such ExpressCard controllers are in fact internal USB hubs in ExpressCard form factor. That means they do not add actual USB bandwidth to the system. All USB 3.0 ExpressCard are controllers.

If you plan getting additional high-speed USB controller, we strongly recommend that you get a USB 3.0 controller, just to be on the safe side.

When setting up a USB 3.0 controller, make sure you configure it to handle USB 2.0 traffic (as opposed to passing USB 2.0 to integrated USB 2.0 controllers in your chipset). There should be a corresponding setting in driver properties or in BIOS.

Known compatibility issues

Combinations of camera & USB chip listed below have known compatibility issues. Unfortunately, there is no guarantee that other combinations will work for sure, but most will. If you need an additional USB controller for connecting specific camera, be sure not to get the one based on incompatible USB chip.